1. Field of the Invention
The present invention pertains to surgical instruments and, more particularly, to a surgical cutting instrument for use in cutting and evacuating material from parts and organs of animal and human bodies.
2. Discussion of the Prior Art
Recently, surgical instruments have been designed to aid ophthalmic surgeons in removing vitreous, blood clots cataracts, lenses and other matter from the eye. Such instruments have utilized pulsating fluid jets, as exemplified by U.S. Pat. Nos. 3,732,858 and 3,996,935 to Banko and Nos. 3,930,505 and 4,024,866 to Wallach, or mechanical cutting or shearing mechanisms, such as reciprocating members, as exemplified by U.S. Pat. No. 3,776,238 to Peyman et al, No. 3,884,238 to O'Malley et al, No. 3,994,297 to Kopf and No. 4,011,869 to Seiler, Jr., or rotating members, as exemplified by U.S. Pat. No. 3,732,858 to Banko, No. 3,734,099 to Bender et al, No. 3,882,872 to Douvas et al, No. 3,844,272 to Banko, No. 3,906,954 to Baehr et al, No. 3,945,375 to Banko, No. 3,976,077 to Kerfoot, Jr., No. 3,990,453 to Douvas et al, and No. 4,002,169 to Cupler II. The prior art surgical instruments, as exemplified by the above noted patents, have been well received in general; however, the prior art surgical instruments have the disadvantages of being quite expensive since they have been invariably constructed of specially designed cutting members requiring detailed machining and specially designed coupling assemblies, of providing inadequate suction due to suction line losses and the restricted cross sectional flow area of the probe of the instrument which desirably has a very small diameter, on the order of 0.005 inch, and of being awkward to handle due to their size and the precise suction control required. In other words, while prior art surgical cutting instruments have the potential for facilitating various surgical operations on the eye and other portions of the body, that potential has, as yet, not been fulfilled since, optimally, such instruments should be easy to handle and operate while permitting precision cutting and suction control and being relatively trouble free, and the prior art surgical cutting instruments have not had these attributes. A particular trouble spot in prior art surgical cutting instruments is that they frequently become clogged with cut tissue during surgical procedures therefore requiring the probe to be removed from the incision to permit cleaning thereof or insertion of a new probe.